Regulator for electric motors



(No Model.)

2 L. L W K G 0 T S W L REGULATOR POR BLEGTRIGMOTORS.

` Patented Jan. 22, 1884.

lll

Ill

III/I Homey/S llllllll/Illllllnllllllllllllllll Illa/1 By his WITNESSES (No Model.) 2 Sheets-S'heet. L. lW. STOCKWELL, REGULATOR FOR ELETRIQI MTORS.

N0.,292,382. Patented JmL-22, i884.

, WITNSSES INVENTOR l LGVL' W Stockwell w By his .fforneys Uivrrnn Sterns Fvraivr LEVI V". STOCK`WELL, OF ClilYlLi-tflk OHI.

REGULATOQFOR ELECTRlC MOTORS.

SPECIFICATION forming part of Letters Patent No. 292,392, dated January 22, 188i'. Application lileLl September '21, 1853. (Xo model.)

To all who/1t it may crm/cern,.-

Be it known that I, Lnvr W. Srockwnm., a citizen of the United States, residing in Cleveland, in the State of Ohio, have invented certain new and useful Improvements in Begulaters for Electric Motors, oi` which the following is a specication.

rlhe object of my invention is to provide an etticient arrangement by which a number of motors may be connected in series in an 'electric circuit and each motor only receive the portion of the current required for its operation.

The details of myinvention are set forth below.

ln the accompanying drawings, Figure l is aplan view of my resistance-regulator; Fig. 2, an inverted or bottom view of the resistancebars. Fig. 3 is a longitudinal section. Fig. 4 is a transverse section. Fig. 5 is a detail view, showing one end of a carbon resistancebar in its bracket or socket; and Fig. 6 is a diagram view, representing a number of motors connected in series in a circuit.

The motors A are placed in the circuit a, and are shunted by adjustable resistances B. rFhe circuit-wire is connected with a bindingpost, b, on the face-plate oi' the variable resistance, and from thence the circuit runs to a post, c, which forms the pivot of the switchnger d, and is in electrical connection therewith. From thep ost c the circuit runs through the motor M to the binding-post e, and from thence through a binding-post, e.

The adjustable resistance, which constitutes a shunt around the mot-or, is composed of a series of resistances, ff, of gradually-decreasing conductivity. These resistances f f are preferably composed of carbon bars, and are arranged in series with a uniformly-decreasing cross-section from left to right, having reference to Fig. l.

Suitable contacts, lettered to correspond with the resistance-bars and electrically connected therewith, project from the face of the instrument and are swept by the Switch-tinger d. This ringer is normally drawn over by a spring, d', so as to rest upon the contact,

but may be operated by a cord passing over a pulley, di, or other suitable device, so as to move it to the right, and put it in electrical connection with any ot' the series of contacts j". With the iingcr d resting on the contact f, which is connected with the post c,as shown, the circuit passes directly from the post b through the ringer, and out at the post e, and no current passes through the motor. By moving the switch-iinger to the left, however, one or more ofthe resistance-barsf is thrown vinto the circuit, and the current divides proportionally to the relative resistance of the motor and the adjustable resistance, and the motor is operated, its power being regulated by the extent of movement of the switch-iinger.

l have shown and described the carbon resistance-strips as gradually decreasing in crosssection from the left to the right of the instrument. By this construction a relatively-greater increased resistance is thrown into the circuit as the switch-finger passes successively from one contact-button f to the other. A wide range of control is therefore afforded with a comparatively-limited movement ot' the lever. The carbon resistance-bars are mounted in metallic brackets i, which are secured to the back of the frontplate of the instrument, as clearly shown in the drawings.

ln order to insure a perfect connection between t-he ends of the carbon bars and the metallic brackets, l electroplate the ends of the bars and insert them tightly into the brackets. A stop7 a, (shown in Figs. l and 2,) limits the movement of the switch-linger in one direction, while the post e limits it in the other direction.

Vith the construction described be arranged in series and worked advantage as if they were connected in multiple arc. Of course the details of construction may be varied in some respects without departing from the invent-ion.

Motors connected in series, as here described, are well adapted for the running ot' light machinery-sueh as sewing-machines, small lathes, drills, Sc-and they maybe controlled by having the ordinary treadle oi' such instruments act upon the cord which passes over the pulley (Z2.

motors may to as much NJA The spring` d may be detached or omitted when desired, and then the finger (l will remain in any position in which it is placed. v

I claim as my nventionl. The combination, substantially as set forth, of an electric circuit, a series of electric motors placed therein, a variable resist-ance placed in ashunt around each motor, and consisting of a series of resistances and a switch connected with the main line on one side of the motor which traverses them, and a contact, also, in the path of said switch connected with theliue on the other sideoi' the motor, for short-circuiting` the motor out of the line.

2. rI'he combination, substantially as set forth, of an electric circuit, a seriesof electrically-connected resistance-bars gradually decreasing Vin cross -section, their contacts, a switch-finger connected with the line, which sweeps all of said contacts, so as to include one or all in the circuit, and a contact also in the path of the switch-finger, through which the circuit may be completed to cut out allot' the resistances.

3. The combination, substantially as set forth, of the face-plate or supporting-board of theadjustable resistance, the resistance-bar,

supporting-brackets mounted on the under -inger which sweeps said contacts, so as to include one or all in the circuit.

et. The combination, substantially as set forth, of an electric circuit, 'an electric motor placed therein, an adjustable resistance placed in a shunt around said motor, the switch-tingcr ot' said adjustable resistance, which is automatically normally held into position to short-,circuit the motor out of the main circuit, and means for moving said switch-finger to throw the resistance into the shunt-circuit and cause more or less ofthe current to pass through the motor.

In testimony whereof I have hereunto subscribed my name this 17th day of September, A. D. 1883.

LEVI 'W. STOGKWELL.

Vitnesses:

^ D. DAVIDSON,

E. C. DAyrDsoN. 

